<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        html, body {height: 100%;width: 100%;box-sizing: border-box;overflow: hidden;margin: 0;padding: 0;border: 0;}
    </style>
    <script>
        window.onload = function () {
            var height = window.screen.height;
            height = height * 0.45;
            document.getElementById("player").setAttribute("height", height + "px");
            document.body.append(height);
        };
    </script>
</head>
<body>
<div>
    <div>
        <ul>
            <li>Ai 换脸</li>
            <li>Ai 换脸</li>
            <li>Ai 换脸</li>
            <li>Ai 换脸</li>
            <li>Ai 换脸</li>
            <li>Ai 换脸</li>
            <li>Ai 换脸</li>
            <li>Ai 换脸</li>
            <li>Ai 换脸</li>
            <li>Ai 换脸</li>
            <li>Ai 换脸</li>
            <li>Ai 换脸</li>
            <li>Ai 换脸</li>
            <li>Ai 换脸</li>
            <li>Ai 换脸</li>
            <li>Ai 换脸</li>
            <li>Ai 换脸</li>
            <li>Ai 换脸</li>
            <li>Ai 换脸</li>
            <li>Ai 换脸</li>
            <li>Ai 换脸</li>
            <li>Ai 换脸</li>
        </ul>
    </div>
    <video id="player" width="100%" height="250px" controls>
        <source src="v/655dc723e047252444161b55e1334cb0.mp4">
    </video>

    <div>
        dfd
        df
        df
    </div>
</div>
</body>
</html>